Code review cleanups:
* Get rid of unused "NOT_LOGGED_IN" string
* Use 400 for generic failures instead of 403
* Return 401 if the package upload is unauthorized
Added a few helpful comments.
Show published date in registry listing
Pull private functions to test using rewire instead of exporting them from module
Refresh extension listing when upload succeeds
Move version to after extension name. Make things look nicer when description is missing.
Also put date with name
Merge pull request #19 from adobe/nj/upload-fixes

Refresh extension listing on upload; show publish date in listing